The present invention relates to apparatuses and methods for radio communications.
One of methods for eliminating interference generated between a plurality of radio base stations when one station is transmitting and the other is receiving data is disclosed in the Unexamined Japanese Patent Publication No5-308333, etc. This example seeks to increase a communication capacity by carrying out frame synchronization between a plurality of base stations, synchronizing the timing of transmission slots and reception slots between the base stations and thus eliminating interference between the base stations.
On the other hand, as an interference signal elimination apparatus, an adaptive antenna reception apparatus disclosed in the Unexamined Japanese Patent Publication No62-241404, etc. is known. This example seeks to correctly receive a transmission signal from a desired mobile station by using unique words in a transmission signal transmitted from the mobile station to a base station as a reference signal to update and combine weighting coefficients of different antennas.
However, a conventional frame synchronization system controls the transmission timing in such a way that the transmission timing of a desired mobile station and that of an interference mobile station coincide completely. Thus, with a reception apparatus such as an adaptive antenna reception apparatus that eliminates the transmission signal from the interference mobile station (hereinafter referred to as xe2x80x9cinterference wavexe2x80x9d) using unique words transmitted from the other mobile station, the self station receives unique words of the desired mobile station and those of the interference mobile station at the same timing, which gives rise to cross talks preventing correct reception of a transmission signal from the desired mobile station (hereinafter referred to as xe2x80x9cdesired wavexe2x80x9d).
It is an object of the present invention to provide a radio communication apparatus and radio communication method capable, even if a mobile station of the self station and another mobile station of a peripheral transmission station use identical unique words, of extracting a received signal from the mobile station of the self station.
This object is achieved by a radio communication apparatus that carries out communications with a desired mobile station at a second transmission timing having an offset over a first transmission timing calculated from at least one transmission timing selected from a group of self station, desired mobile station, interference station and interference mobile station.